drivers/input/touchscreen/wm831x-ts.c

   1 /*
   2  * Touchscreen driver for WM831x PMICs
   3  *
   4  * Copyright 2011 Wolfson Microelectronics plc.
   5  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   6  *
   7  * This program is free software; you can redistribute  it and/or modify it
   8  * under  the terms of  the GNU General  Public License as published by the
   9  * Free Software Foundation;  either version 2 of the  License, or (at your
  10  * option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/string.h>
  18 #include <linux/pm.h>
  19 #include <linux/input.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/io.h>
  22 #include <linux/mfd/wm831x/core.h>
  23 #include <linux/mfd/wm831x/irq.h>
  24 #include <linux/mfd/wm831x/pdata.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28
  29 /*
  30  * R16424 (0x4028) - Touch Control 1
  31  */
  32 #define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
  33 #define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
  34 #define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
  35 #define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
  36 #define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
  37 #define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
  38 #define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
  39 #define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
  40 #define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
  41 #define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
  42 #define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
  43 #define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */
  44
  45 /*
  46  * R16425 (0x4029) - Touch Control 2
  47  */
  48 #define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
  49 #define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
  50 #define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
  51 #define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
  52 #define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
  53 #define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
  54 #define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */
  55
  56 /*
  57  * R16426-8 (0x402A-C) - Touch Data X/Y/X
  58  */
  59 #define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
  60 #define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
  61 #define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
  62 #define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */
  63
  64 struct wm831x_ts {
  65         struct input_dev *input_dev;
  66         struct wm831x *wm831x;
  67         unsigned int data_irq;
  68         unsigned int pd_irq;
  69         bool pressure;
  70         bool pen_down;
  71         struct work_struct pd_data_work;
  72 };
  73
  74 static void wm831x_pd_data_work(struct work_struct *work)
  75 {
  76         struct wm831x_ts *wm831x_ts =
  77                 container_of(work, struct wm831x_ts, pd_data_work);
  78
  79         if (wm831x_ts->pen_down) {
  80                 enable_irq(wm831x_ts->data_irq);
  81                 dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
  82         } else {
  83                 enable_irq(wm831x_ts->pd_irq);
  84                 dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
  85         }
  86 }
  87
  88 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
  89 {
  90         struct wm831x_ts *wm831x_ts = irq_data;
  91         struct wm831x *wm831x = wm831x_ts->wm831x;
  92         static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
  93         u16 data[3];
  94         int count;
  95         int i, ret;
  96
  97         if (wm831x_ts->pressure)
  98                 count = 3;
  99         else
 100                 count = 2;
 101
 102         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 103                         WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 104
 105         ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
 106                                data);
 107         if (ret != 0) {
 108                 dev_err(wm831x->dev, "Failed to read touch data: %d\n",
 109                         ret);
 110                 return IRQ_NONE;
 111         }
 112
 113         /*
 114          * We get a pen down reading on every reading, report pen up if any
 115          * individual reading does so.
 116          */
 117         wm831x_ts->pen_down = true;
 118         for (i = 0; i < count; i++) {
 119                 if (!(data[i] & WM831X_TCH_PD)) {
 120                         wm831x_ts->pen_down = false;
 121                         continue;
 122                 }
 123                 input_report_abs(wm831x_ts->input_dev, data_types[i],
 124                                  data[i] & WM831X_TCH_DATA_MASK);
 125         }
 126
 127         if (!wm831x_ts->pen_down) {
 128                 /* Switch from data to pen down */
 129                 dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
 130
 131                 disable_irq_nosync(wm831x_ts->data_irq);
 132
 133                 /* Don't need data any more */
 134                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 135                                 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 136                                 WM831X_TCH_Z_ENA, 0);
 137
 138                 /* Flush any final samples that arrived while reading */
 139                 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 140                                 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
 141
 142                 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
 143
 144                 if (wm831x_ts->pressure)
 145                         input_report_abs(wm831x_ts->input_dev,
 146                                          ABS_PRESSURE, 0);
 147
 148                 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
 149
 150                 schedule_work(&wm831x_ts->pd_data_work);
 151         }
 152
 153         input_sync(wm831x_ts->input_dev);
 154
 155         return IRQ_HANDLED;
 156 }
 157
 158 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
 159 {
 160         struct wm831x_ts *wm831x_ts = irq_data;
 161         struct wm831x *wm831x = wm831x_ts->wm831x;
 162         int ena = 0;
 163
 164         if (wm831x_ts->pen_down)
 165                 return IRQ_HANDLED;
 166
 167         disable_irq_nosync(wm831x_ts->pd_irq);
 168
 169         /* Start collecting data */
 170         if (wm831x_ts->pressure)
 171                 ena |= WM831X_TCH_Z_ENA;
 172
 173         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 174                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
 175                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
 176
 177         input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
 178         input_sync(wm831x_ts->input_dev);
 179
 180         wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
 181                         WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
 182
 183         wm831x_ts->pen_down = true;
 184
 185         /* Switch from pen down to data */
 186         dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
 187         schedule_work(&wm831x_ts->pd_data_work);
 188
 189         return IRQ_HANDLED;
 190 }
 191
 192 static int wm831x_ts_input_open(struct input_dev *idev)
 193 {
 194         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 195         struct wm831x *wm831x = wm831x_ts->wm831x;
 196
 197         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 198                         WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
 199                         WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 200                         WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
 201
 202         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 203                         WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
 204
 205         return 0;
 206 }
 207
 208 static void wm831x_ts_input_close(struct input_dev *idev)
 209 {
 210         struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
 211         struct wm831x *wm831x = wm831x_ts->wm831x;
 212
 213         /* Shut the controller down, disabling all other functionality too */
 214         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 215                         WM831X_TCH_ENA | WM831X_TCH_X_ENA |
 216                         WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
 217
 218         /* Make sure any pending IRQs are done, the above will prevent
 219          * new ones firing.
 220          */
 221         synchronize_irq(wm831x_ts->data_irq);
 222         synchronize_irq(wm831x_ts->pd_irq);
 223
 224         /* Make sure the IRQ completion work is quiesced */
 225         flush_work_sync(&wm831x_ts->pd_data_work);
 226
 227         /* If we ended up with the pen down then make sure we revert back
 228          * to pen detection state for the next time we start up.
 229          */
 230         if (wm831x_ts->pen_down) {
 231                 disable_irq(wm831x_ts->data_irq);
 232                 enable_irq(wm831x_ts->pd_irq);
 233                 wm831x_ts->pen_down = false;
 234         }
 235 }
 236
 237 static __devinit int wm831x_ts_probe(struct platform_device *pdev)
 238 {
 239         struct wm831x_ts *wm831x_ts;
 240         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 241         struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
 242         struct wm831x_touch_pdata *pdata = NULL;
 243         struct input_dev *input_dev;
 244         int error;
 245
 246         if (core_pdata)
 247                 pdata = core_pdata->touch;
 248
 249         wm831x_ts = kzalloc(sizeof(struct wm831x_ts), GFP_KERNEL);
 250         input_dev = input_allocate_device();
 251         if (!wm831x_ts || !input_dev) {
 252                 error = -ENOMEM;
 253                 goto err_alloc;
 254         }
 255
 256         wm831x_ts->wm831x = wm831x;
 257         wm831x_ts->input_dev = input_dev;
 258         INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
 259
 260         /*
 261          * If we have a direct IRQ use it, otherwise use the interrupt
 262          * from the WM831x IRQ controller.
 263          */
 264         if (pdata && pdata->data_irq)
 265                 wm831x_ts->data_irq = pdata->data_irq;
 266         else
 267                 wm831x_ts->data_irq = platform_get_irq_byname(pdev, "TCHDATA");
 268
 269         if (pdata && pdata->pd_irq)
 270                 wm831x_ts->pd_irq = pdata->pd_irq;
 271         else
 272                 wm831x_ts->pd_irq = platform_get_irq_byname(pdev, "TCHPD");
 273
 274         if (pdata)
 275                 wm831x_ts->pressure = pdata->pressure;
 276         else
 277                 wm831x_ts->pressure = true;
 278
 279         /* Five wire touchscreens can't report pressure */
 280         if (pdata && pdata->fivewire) {
 281                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 282                                 WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
 283
 284                 /* Pressure measurements are not possible for five wire mode */
 285                 WARN_ON(pdata->pressure && pdata->fivewire);
 286                 wm831x_ts->pressure = false;
 287         } else {
 288                 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 289                                 WM831X_TCH_5WIRE, 0);
 290         }
 291
 292         if (pdata) {
 293                 switch (pdata->isel) {
 294                 default:
 295                         dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
 296                                 pdata->isel);
 297                         /* Fall through */
 298                 case 200:
 299                 case 0:
 300                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 301                                         WM831X_TCH_ISEL, 0);
 302                         break;
 303                 case 400:
 304                         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 305                                         WM831X_TCH_ISEL, WM831X_TCH_ISEL);
 306                         break;
 307                 }
 308         }
 309
 310         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
 311                         WM831X_TCH_PDONLY, 0);
 312
 313         /* Default to 96 samples/sec */
 314         wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
 315                         WM831X_TCH_RATE_MASK, 6);
 316
 317         error = request_threaded_irq(wm831x_ts->data_irq,
 318                                      NULL, wm831x_ts_data_irq,
 319                                      IRQF_ONESHOT,
 320                                      "Touchscreen data", wm831x_ts);
 321         if (error) {
 322                 dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
 323                         wm831x_ts->data_irq, error);
 324                 goto err_alloc;
 325         }
 326         disable_irq(wm831x_ts->data_irq);
 327
 328         error = request_threaded_irq(wm831x_ts->pd_irq,
 329                                      NULL, wm831x_ts_pen_down_irq,
 330                                      IRQF_ONESHOT,
 331                                      "Touchscreen pen down", wm831x_ts);
 332         if (error) {
 333                 dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
 334                         wm831x_ts->pd_irq, error);
 335                 goto err_data_irq;
 336         }
 337
 338         /* set up touch configuration */
 339         input_dev->name = "WM831x touchscreen";
 340         input_dev->phys = "wm831x";
 341         input_dev->open = wm831x_ts_input_open;
 342         input_dev->close = wm831x_ts_input_close;
 343
 344         __set_bit(EV_ABS, input_dev->evbit);
 345         __set_bit(EV_KEY, input_dev->evbit);
 346         __set_bit(BTN_TOUCH, input_dev->keybit);
 347
 348         input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
 349         input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
 350         if (wm831x_ts->pressure)
 351                 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
 352
 353         input_set_drvdata(input_dev, wm831x_ts);
 354         input_dev->dev.parent = &pdev->dev;
 355
 356         error = input_register_device(input_dev);
 357         if (error)
 358                 goto err_pd_irq;
 359
 360         platform_set_drvdata(pdev, wm831x_ts);
 361         return 0;
 362
 363 err_pd_irq:
 364         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 365 err_data_irq:
 366         free_irq(wm831x_ts->data_irq, wm831x_ts);
 367 err_alloc:
 368         input_free_device(input_dev);
 369         kfree(wm831x_ts);
 370
 371         return error;
 372 }
 373
 374 static __devexit int wm831x_ts_remove(struct platform_device *pdev)
 375 {
 376         struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
 377
 378         free_irq(wm831x_ts->pd_irq, wm831x_ts);
 379         free_irq(wm831x_ts->data_irq, wm831x_ts);
 380         input_unregister_device(wm831x_ts->input_dev);
 381         kfree(wm831x_ts);
 382
 383         platform_set_drvdata(pdev, NULL);
 384         return 0;
 385 }
 386
 387 static struct platform_driver wm831x_ts_driver = {
 388         .driver = {
 389                 .name = "wm831x-touch",
 390                 .owner = THIS_MODULE,
 391         },
 392         .probe = wm831x_ts_probe,
 393         .remove = __devexit_p(wm831x_ts_remove),
 394 };
 395
 396 static int __init wm831x_ts_init(void)
 397 {
 398         return platform_driver_register(&wm831x_ts_driver);
 399 }
 400 module_init(wm831x_ts_init);
 401
 402 static void __exit wm831x_ts_exit(void)
 403 {
 404         platform_driver_unregister(&wm831x_ts_driver);
 405 }
 406 module_exit(wm831x_ts_exit);
 407
 408 /* Module information */
 409 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 410 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
 411 MODULE_LICENSE("GPL");
 412 MODULE_ALIAS("platform:wm831x-touch");